CN103194063B - Trapezoidal polysiloxane modified thermosetting resin and preparation method thereof - Google Patents

Abstract

The invention discloses a trapezoidal polysiloxane modified thermosetting resin and a preparation method thereof. By weight, 100 parts of molten thermosetting resin and 1-50 parts of trapezoidal polysiloxane are uniformly mixed and cured so as to obtain the trapezoidal polysiloxane modified thermosetting resin. The trapezoidal polysiloxane contains a great deal of phosphaphenanthrene structures and amino groups. The preparation method comprises the following steps that: phosphaphenanthrene trialkoxy silane and a silane coupling agent of another active group are directly mixed and hydrolyzed, furthermore the trapezoidal polysiloxane is prepared in the hydrolysis velocity of a grading control system. The method can be used for effectively avoiding the process in the prior art that a template needs to be removed, simplifying the operation process and improving the yield. Compared with an unmodified resin, the obtained modified thermosetting resin is greatly improved in inflaming retarding property and vitrification conversion temperature, and has more excellent size stability. The preparation method of the modified thermosetting resin has the characteristics of wide applicability and simplicity in operation process.

Description

A kind of trapezoidal polysiloxane modified thermosetting resin and its preparation method

technical field

The invention relates to a modified thermosetting resin and a preparation method thereof, in particular to a preparation method of a trapezoidal polysiloxane modified thermosetting resin.

Background technique

Thermosetting resin is a kind of cross-linked polymer material with a network structure. Its unique structure endows it with excellent comprehensive properties, such as outstanding heat resistance and thermal oxidation stability, excellent comprehensive mechanical properties and good resistance to heat and humidity. properties, chemical resistance and dielectric properties, so it occupies an indispensable and important position in cutting-edge industrial fields such as aerospace, electronic information, and electrical insulation. However, they also have the disadvantages of poor flame retardancy and poor thermal dimensional stability of cured products. For many cutting-edge applications, flammability and poor thermal dimensional stability have become the "bottleneck" restricting their application , so the modification of their flame retardancy and thermal dimensional stability is the focus of the research field of thermosetting resins in recent years.

In order to improve the flame retardancy of thermosetting resins, a lot of research work has been done at home and abroad. At present, the proposed modification methods mainly fall into two categories: intrinsic method and additive method. The intrinsic method is to introduce rigid or flame retardant groups into the molecular structure of the thermosetting resin to achieve the purpose of modification, but this method is difficult to operate and has limitations; while the additive method is to add inorganic fillers or various flame retardants To achieve the improvement of thermosetting resin flame retardancy. Since it is difficult to obtain good dispersion of inorganic fillers in thermosetting resins, it needs to be added in a very high amount (50-70wt%) to obtain suitable flame retardant properties, which inevitably sacrifices the original properties of thermosetting resins. Such as processability, mechanical properties and dielectric properties. Phosphorus-based flame retardants are widely used in the field of flame-retardant modification of thermosetting resins due to their high flame-retardant efficiency, long-lasting effect and low toxicity. Phosphorus-based flame retardants can be divided into inorganic phosphorus-containing flame retardants and organic phosphorus-containing flame retardants. Among them, the disadvantages of inorganic phosphorus-containing flame retardants are similar to those of the above-mentioned inorganic fillers, and they have poor thermal stability and high hygroscopicity. (Bin Zhao, Zhi Hu, Li Chen, Yun Liu, Ya Liu, Yuzhong Wang. A phosphorus-containing Inorganic compound as an effective flame retardant for glass-fiber-reinforced polyamide 6. Journal of Applied Polymer Science 2011; 119: 2379-2385). However, organic phosphorus-containing flame retardants cannot contribute to improving the thermal dimensional stability and thermal stability of the matrix resin, mainly because the existing organic phosphorus-containing flame retardants themselves do not have a highly regular structure with good thermal dimensional stability. , and phosphorus has a certain flammability (Brehme S, Schartel B, Goebbels J, Fischer O, Pospiech D, Bykov Y, Döring M. Phosphorus polyester versus aluminum phosphate in poly(butylene terephthalate) (PBT): flame retardancy performance and mechanisms. Polymer Degradation and Stability 2011, 96:875-884.). Therefore, how to make organic phosphorus-containing flame retardants not only impart flame retardancy to thermosetting resins, but also take into account the thermal dimensional stability of the resins is of great significance, but there have been no related reports so far.

Chinese invention patent (CN102199294A) discloses a hyperbranched polysiloxane containing a phosphaphenanthrene structure, which has flame retardancy, but its preparation method is to first prepare a hyperbranched polymer containing an epoxy group, and then The phenanthrene structure is dotted around the hyperbranched polymer, so the obtained hyperbranched polysiloxane has a low phosphorus content, which is not conducive to obtaining excellent flame retardant efficiency at low content. In addition, the reaction between the phosphaphenanthrene group and the epoxy-based hyperbranched polymer needs to be carried out at a relatively high temperature (>80°C), so the reaction system is very prone to gelation, resulting in the failure of the product synthesis. It is worth noting that according to previous studies, the thermal dimensional stability of composite materials is determined by the linear thermal expansion coefficient (CTE) of each component and the interface properties between phases (Wang S, Liang Z, Gonnet P, Liao YH, Wang B, Zhang C. Effect of Nanotube Functionalization on the Coefficient of Thermal Expansion of Nanocomposites. Advanced Functional Materials 2007, 17:87-92.); and the CTE value of each component depends on the strength of molecular structure movement ability (Sergei S, Nachiket R, Rahmi O, Pawel K. Using vibrational mode analysis for predicting the coefficient of thermal expansion of amorphous polymers. Journal of Polymer Science: Part B: Polymer Physics 2009, 47:2114-2121.). The research on hyperbranched polysiloxane shows that the crosslink density and glass transition temperature of the modified system are significantly reduced, and the impact strength is greatly improved (see literature ① Zhiyong Zhang, Aijuan Gu, Guozheng Liang, Li Yuan, Dongxian Zhuo. A novel hyperbranched polysiloxane containing epoxy and phosphaphenanthrene groups and its multi-functional modification of cyanate ester resin. Soft Materials 2013, 11:346-352. ②Dongxian Zhuo, Aijuan Gu, Guozheng Liang, Jiangtao Hu, Li Yuan, Lifu Ji. Novel hyperbranched polyphenylsilsesquioxane-modified cyanate ester resins with improved toughness and stiffness. Polymer International 2011, 60:1277-1286.), this is because hyperbranched polysiloxane contains many cavity structures, and contains many branched structures composed of flexible -Si-O-Si-chain segments , so that the mobility of the modified polymer network does not decrease but increases. The improvement of the system's motion ability will directly lead to the decrease of the thermal dimensional stability of the modified resin.

Therefore, how to endow the modified resin with outstanding thermal dimensional stability and high-efficiency flame retardancy is a meaningful research topic.

Contents of the invention

In order to overcome the shortcomings of existing modified thermosetting resins, the present invention provides a trapezoidal polysiloxane modified thermosetting resin with high-efficiency flame retardancy and high thermal dimensional stability and a preparation method thereof.

In order to realize the purpose of the present invention, the adopted technical scheme is: provide a kind of ladder polysiloxane modified thermosetting resin, by weight, it comprises 100 parts of thermosetting resin and 1～50 parts of ladder polysiloxane; Ladder polysiloxane contains both phosphaphenanthrene structure and amino groups, and its structural formula is:

,

In the formula, is the omitted segment;

R is R ₁ or R ₂ , wherein,

The ladder polysiloxane molecular chain contains both R1 and R2, and R1 is not adjacent to the same side of the ladder polysiloxane molecular chain; the molecular weight of the ladder polysiloxane is 900-3,000,000.

The technical solution of the present invention also includes a preparation method of the above-mentioned trapezoidal polysiloxane modified thermosetting resin, comprising the following steps:

1. Under the protection of an inert gas, couple 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with a molar ratio of 0.9:1 to 1.1:1 with vinyl-containing silane Agents are mixed to obtain mixture A;

2. According to the mass ratio of 1:50 to 1:100, mix the initiator with the mixture A to obtain the mixture B;

3. According to the mass concentration of 0.2 ~ 0.5 g/mL Dissolve the mixture B in the solvent S1, and stir at a constant temperature of 30-120°C for 2-20 hours. After the reaction is completed, the solvent is distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure;

4. Under the protection of an inert gas, mix the phosphophenanthrene structure-containing silane coupling agent prepared in step (3) with the amino group-containing silane coupling agent at a mass ratio of 1:1 to 1:3 to obtain a mixture C; Mix the catalyst and the mixture C at a mass ratio of 1:50 to 1:100 to obtain a mixture D; mix the mixture D with the solvent S2 at a mass concentration of 0.2 to 0.5 g/mL, stir at room temperature for 0.5 to 3 hours, and heat up to 40 to Stir at 100°C for 0.5 to 10 hours at a constant temperature; after the reaction is completed, a mixture E is obtained;

5. According to the volume ratio of 1:5 to 1:20, slowly drop the mixture E into the solvent S3, and a white precipitate is precipitated, filtered, washed, and dried to obtain a trapezoidal polysiloxane;

6. Mix 100 parts of melted heat-curable resin and 1-50 parts of trapezoidal polysiloxane evenly, and after curing, the heat-curable resin is a resin that can be heat-cured by itself, or a resin that cannot be heat-cured by itself. A resin system composed of a curing agent is obtained to obtain a trapezoidal polysiloxane modified thermosetting resin.

The optimized technical scheme of the present invention is:

The inert gas is argon, nitrogen or helium.

The silane coupling agent containing vinyl is vinyldimethoxysilane, vinyltriethoxysilane or γ-methacryloxypropyltrimethoxysilane.

The initiator is one of azobisisobutyronitrile, azobisisoheptanonitrile, azobiscyclohexylcarbonitrile, dimethyl azobisisobutyrate or a combination thereof.

The initiator is one of dibenzoyl peroxide, dicumyl peroxide, lauryl peroxide, tert-butyl peroxybenzoate or a combination thereof.

The amino group-containing silane coupling agent is 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane.

The catalyst is methanol solution of potassium hydroxide or sodium hydroxide.

The solvent S1 is C ₁ -C ₃ alcohol, acetone, acetonitrile, dichloromethane, chloroform, benzene, toluene, tetrahydrofuran, dimethylformamide or a combination thereof.

The solvent S2 or S3 is deionized water, C ₁ -C ₃ alcohol, acetone, acetonitrile, chloroform or a combination thereof.

Compared with prior art, the beneficial effect that the present invention obtains is:

1. The modifying agent used in the present invention is a modifying agent which is organically combined with trapezoidal polysiloxane and phosphaphenanthrene structure. Its phosphorus content is high, which ensures that the modified resin has high resistance at low additions. Flammability; at the same time, the structure of ladder polysiloxane with excellent thermal dimensional stability ensures that the modified resin has outstanding thermal stability.

2. The adopted ladder-shaped polysiloxane contains amino groups, so that the ladder-shaped polysiloxane has good dispersion in the resin, which is conducive to the full play of the modification effect.

3. The preparation process of trapezoidal polysiloxane and modified resin is simple and controllable, and has wide applicability.

Description of drawings

Fig. 1 is the FT-IR spectrogram of the silane coupling agent containing phosphaphenanthrene structure, 3-aminopropyltriethoxysilane and ladder polysiloxane provided by Example 1 of the present invention;

Fig. 2 is the ¹ H-NMR spectrogram of the ladder polysiloxane provided in Example 1 of the present invention;

Fig. 3 is the ²⁹ Si-NMR spectrogram of the ladder polysiloxane provided by Example 1 of the present invention;

Fig. 4 is the XRD spectrogram of the trapezoidal polysiloxane provided by Example 1 of the present invention;

Fig. 5 is the thermal expansion coefficient curve comparison chart of the bismaleimide resin prepared by the comparative example of the present invention and the ladder polysiloxane modified bismaleimide resin prepared by Examples 1-4;

Fig. 6 is a bar graph comparing the limiting oxygen index of the bismaleimide resin prepared in the comparative example of the present invention and the ladder polysiloxane-modified bismaleimide resin prepared in Examples 1-4.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1

1. Synthesis of trapezoidal polysiloxane

(1) Under nitrogen protection, 1.9g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), 1.9g of vinyltriethoxysilane, 0.08g of Add nitrogen diisoheptanonitrile and 10 mL dimethylformamide into the flask, and react at 120° C. for 2 hours. After the reaction, the solvent was distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure.

(2) Under the protection of nitrogen, 3g of silane coupling agent containing phosphaphenanthrene structure, 3g of 3-aminopropyltriethoxysilane, 0.1g of sodium hydroxide in methanol (0.1mg/mL), 20mL of Ionized water and 7 mL of methanol were added to the flask, and reacted at room temperature for 0.5 hours; then the temperature was raised to 40°C for 10 hours. After the reaction, the product was slowly dropped into methanol at a volume ratio of 1:5 to precipitate a white powder, which was filtered, washed, and dried to obtain a trapezoidal polysiloxane with a molecular weight of 22360 and a phosphorus content of 7.6 wt%. Its FT-IR, XRD, ¹ H-NMR and ²⁹ Si-NMR spectra are shown in Figures 1, 2, 3 and 4, respectively.

Referring to accompanying drawing 1, it is the FT-IR spectrogram of the silane coupling agent containing phosphaphenanthrene structure, 3-aminopropyltriethoxysilane and ladder polysiloxane provided in this embodiment. It can be seen from the figure that the silane coupling agent containing phosphaphenanthrene structure and 3-aminopropyltriethoxysilane present the stretching vibration peak of Si-OC bond at 1036-1190 cm ^-1 , while the trapezoidal polysiloxane There are two vibrational absorption peaks (1139 and 1041 cm ^-1 ) of the -Si-O-Si- bond in the ladder structure split around 1100 cm ^-1 , indicating that the ladder structure polysiloxane was successfully obtained. Comparing their FT-IR diagrams, it can also be seen that Si-OH (3437cm ^-1 ) appeared in the FT-IR diagram of phosphaphenanthrene ladder polysiloxane, and also appeared with 3-aminopropyltriethoxy The absorption peaks are similar to silane coupling agents with base silane and phosphaphenanthrene structure, including -NH ₂ (3359cm ^-1 ), benzene ring (1600, 1450cm ^-1 ), P-CH ₂ - (1406cm ^-1 ) and P= The characteristic absorption peak of O (1233cm ^-1 ) indicated that the ladder polysiloxane with both phosphaphenanthrene and amino groups was prepared successfully.

See accompanying drawing 2, which is the ¹ H-NMR spectrum of the ladder polysiloxane provided in this example. 7.12-8.39 ppm and 0.59-2.87 ppm are the chemical shifts of hydrogen on the benzene ring and -CH ₂ - respectively, indicating that the synthesized ladder polysiloxane contains phosphaphenanthrene and amino groups.

Referring to accompanying drawing 3, it is the ²⁹ Si-NMR spectrogram of the ladder polysiloxane provided in this example. It can be seen from the figure that the trapezoidal polysiloxane presents ^T3 units at -82.0 and -80.7 ppm ( ^T3 units are Si atoms that have been completely condensed, no hydroxyl groups are connected, and three silicon-oxygen-silicon structures are connected, Figure 3 A and B are the chemical shifts of T3 units), while ^T2 units appear at -75.9 and -74.7 ppm ( ^T2 units are Si atoms connected with a hydroxyl functional group and two silicon-oxygen-silicon structures. C in Figure 3 , D is the chemical shift of the T2 unit), indicating that the prepared polysiloxane is a ladder structure.

Referring to accompanying drawing 4, it is the XRD spectrogram of the ladder polysiloxane provided by this embodiment. There are three peaks in the XRD spectrum at 2θ=6°, 12° and 21°, which are the intramolecular chain (0.5, 0.7 nm) and intermolecular chain (1.4 nm) of the trapezoidal regular structure in ladder polysiloxane. nm) distance, indicating that the synthesized polysiloxane has a regular ladder structure, and the phosphaphenanthrene structure is not adjacent on the same side of the ladder polysiloxane molecular chain.

Based on the above analysis, it can be concluded that the synthesized substance is a trapezoidal polysiloxane containing a phosphaphenanthrene structure and an amino group.

2. Preparation of trapezoidal polysiloxane modified bismaleimide resin

Weigh 45.7g N,N'-4,4'-diphenylmethane bismaleimide and 34.3g O,O'-diallyl bisphenol A in a beaker, mechanically stir at 135°C for prepolymerization After 15 minutes, a brownish-yellow transparent clear liquid was obtained. Add 4.21 g of the ladder polysiloxane prepared in this example (accounting for 5 wt% of the total mass of the resin system) to the liquid, and mechanically stir for 15 minutes to prepolymerize to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuumize at 135°C for 1h, and then follow the processes of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 230°C/4h respectively After curing and post-treatment, a ladder polysiloxane modified bismaleimide resin is obtained. Its thermal expansion coefficient and limiting oxygen index in the glassy state (50-250°C) are shown in Figure 5 and Figure 6, respectively.

Example 2

Weigh 45.7g N,N'-4,4'-diphenylmethane bismaleimide and 34.3g O,O'-diallyl bisphenol A in a beaker, mechanically stir at 135°C for prepolymerization After 15 minutes, a brownish-yellow transparent clear liquid was obtained; 8.89 g of the trapezoidal polysiloxane prepared in Example 1 (accounting for 10 wt% of the total mass of the resin system) was added to the liquid, and the prepolymer was mechanically stirred for 15 minutes to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuumize at 135°C for 1h, and then follow the processes of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 230°C/4h respectively After curing and post-treatment, a ladder polysiloxane modified bismaleimide resin is obtained. Its thermal expansion coefficient and limiting oxygen index in the glassy state (50-250°C) are shown in Figure 5 and Figure 6, respectively.

Example 3

Weigh 45.7g N,N'-4,4'-diphenylmethane bismaleimide and 34.3g O,O'-diallyl bisphenol A in a beaker, mechanically stir at 135°C for prepolymerization After 15 minutes, a brownish-yellow transparent clear liquid was obtained; 14.12 g of the trapezoidal polysiloxane prepared in Example 1 (accounting for 15 wt% of the total mass of the resin system) was added to the liquid, and mechanically stirred for 15 minutes to prepolymerize to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuumize at 135°C for 1h, and then follow the processes of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 230°C/4h respectively After curing and post-treatment, a ladder polysiloxane modified bismaleimide resin is obtained. Its thermal expansion coefficient and limiting oxygen index in the glassy state (50-250°C) are shown in Figure 5 and Figure 6, respectively.

Example 4

Weigh 45.7g N,N'-4,4'-diphenylmethane bismaleimide and 34.3g O,O'-diallyl bisphenol A in a beaker, mechanically stir at 135°C for prepolymerization After 15 minutes, a brownish-yellow transparent clear liquid was obtained; 20 g of the trapezoidal polysiloxane prepared in Example 1 (accounting for 20 wt% of the total mass of the resin system) was added to the liquid, and mechanically stirred for prepolymerization for 15 minutes to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuumize at 135°C for 1h, and then follow the processes of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 230°C/4h respectively After curing and post-treatment, a ladder polysiloxane modified bismaleimide resin is obtained. Its thermal expansion coefficient and limiting oxygen index in the glassy state (50-250°C) are shown in Figure 5 and Figure 6, respectively.

Preparation of comparative example bismaleimide resin: weigh 40g N,N'-4,4'-diphenylmethane bismaleimide and 30g O,O'-diallyl bisphenol A in a beaker , stirred at 135 ° C for 30 minutes to obtain a brownish-yellow transparent clear liquid (prepolymer). Pour the prepolymer into a preheated mold, vacuumize at 135°C for 1h, and then follow the processes of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 230°C/4h Carry out curing and post-treatment to obtain bismaleimide cured resin. Its thermal expansion coefficient and limiting oxygen index in the glassy state (50-250°C) are shown in Figure 5 and Figure 6, respectively.

Refer to accompanying drawing 5, it is the bismaleimide resin prepared in the comparative example and the ladder polysiloxane modified bismaleimide resin thermal expansion coefficient curve comparison chart prepared in Examples 1-4. As can be seen from the figure, the coefficient of thermal expansion of the modified resin is significantly lower than that of the original bismaleimide resin; increased and decreased substantially. This is mainly due to the following two reasons: first, the ladder polysiloxane itself has a highly regular ladder structure and contains a large number of rigid groups (benzene rings), which effectively limit the movement of molecular chains; second, the ladder polysiloxane Containing active amino groups, it can produce chemical linkage with bismaleimide resin, so as to well limit the movement of the polymer network during the heating process, and endow the modified resin with excellent thermal dimensional stability.

Refer to accompanying drawing 6, it is the bismaleimide resin prepared in the comparative example and the trapezoidal polysiloxane modified bismaleimide resin prepared in Examples 1-4, and it is a columnar comparison chart of limiting oxygen index. It can be clearly seen that the limiting oxygen index of bismaleimide resin showed an obvious upward trend because of the addition of ladder polysiloxane. When the addition of ladder polysiloxane was 5wt%, the modified resin Compared with the comparative example, the limiting oxygen index increased by 58%. These data indicate that while improving the thermal dimensional stability of the bismaleimide resin, the ladder polysiloxane can also significantly improve the flame retardancy of the resin. The reason may be that the trapezoidal polysiloxane contains a highly efficient flame-retardant characteristic group (phosphaphenanthrene group). In addition to the condensed phase flame-retardant mechanism and the formation of a surface insulation layer to play a flame-retardant role, it also has a gas-phase flame-retardant effect. . The gas generated by the thermal decomposition of the phosphaphenanthrene group can effectively dilute the flammable gas, and the active groups generated can quickly capture free radicals, thereby blocking the combustion reaction. The combined action of the two flame retardant mechanisms makes the modified resin exhibit excellent and efficient flame retardant properties.

The above data show that the trapezoidal polysiloxane-modified thermosetting resin disclosed in the present invention is a material with both high flame retardancy and high thermal dimensional stability.

Example 5

1. Synthesis of trapezoidal polysiloxane

(1) Under the protection of argon, 2.4g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1.9g vinyldimethoxysilane, 0.7g azobisiso Butyronitrile, 5mL methanol, and 5mL acetonitrile were added to the flask, and reacted at 60°C for 20 hours. After the reaction, the solvent was distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure.

(2) Under the protection of argon gas, 3g of silane coupling agent containing phosphaphenanthrene structure, 9g of 3-aminopropyltrimethoxysilane, 0.1g of potassium hydroxide in methanol solution (0.1mg/mL), 2mL Deionized water, 15 mL of acetone, 15 mL of acetonitrile and 10 mL of chloroform were added to the flask, and reacted at room temperature for 1.5 hours; then the temperature was raised to 55° C. for 7 hours. After the reaction, the product was slowly dropped into methanol at a volume ratio of 1:10 to precipitate a white powder, which was filtered, washed and dried to obtain a trapezoidal polysiloxane with a molecular weight of 37980 and a phosphorus content of 8.7 wt%.

2. Preparation of trapezoidal polysiloxane modified bismaleimide resin

Weigh 45.7g N,N'-4,4'-diphenylmethane bismaleimide and 34.3g O,O'-diallyl bisphenol A in a beaker, mechanically stir at 135°C for prepolymerization After 15 minutes, a brownish-yellow transparent clear liquid was obtained. 2.4 g of the ladder polysiloxane prepared in this example was added to the liquid, and mechanically stirred for prepolymerization for 15 minutes to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuumize at 135°C for 1h, and then follow the processes of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 230°C/4h respectively After curing and post-treatment, a ladder polysiloxane modified bismaleimide resin is obtained.

Example 6

1. Synthesis of trapezoidal polysiloxane

(1) Under the protection of helium, 2.06g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1.9g of vinyltriethoxysilane, 0.02g of azobis Isobutyronitrile, 0.02g Azobisisoheptanonitrile and 20 mL of dichloromethane were added into the flask and reacted at 60°C for 10 hours. After the reaction, the solvent was distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure.

(2) Under the protection of helium, 3 g of phosphaphenanthrene structure-containing silane coupling agent, 3 g of 3-aminopropyltrimethoxysilane, 0.1 g of potassium hydroxide in methanol (0.1 mg/mL), and 2 mL of Ionized water, 20mL ethanol and 20.5mL propanol were added to the flask and reacted at room temperature for 2 hours; then the temperature was raised to 50°C for 10 hours. After the reaction, the product was slowly dropped into a mixed solution of acetone, acetonitrile and chloroform to precipitate a white powder according to a volume ratio of 1:15, and was filtered, washed and dried to obtain a trapezoidal polysiloxane with a molecular weight of 49360. The phosphorus content is 7.9 wt%.

2. Preparation of trapezoidal polysiloxane/cyanate resin

Weigh 60g of bisphenol A type cyanate in a beaker, stir mechanically at 150°C until the cyanate is completely dissolved to obtain a clear liquid; add 15g of the trapezoidal polysiloxane prepared in Example 6 to the liquid, and stir mechanically Prepolymerized for 25 minutes to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuumize at 150°C for 30 minutes, and then follow the processes of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 240°C/4h respectively After curing and post-treatment, a ladder polysiloxane/cyanate resin is obtained.

Example 7

1. Synthesis of trapezoidal polysiloxane

(1) Under the protection of helium, 1.9g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1.9g γ-methacryloxypropyltrimethoxy Silane, 0.03g Lauryl peroxide, 0.05 g of tert-butyl peroxybenzoate, 5 mL of propanol, 2 mL of dichloromethane, and 5 mL of methanol were added to the flask, and reacted at 60° C. for 6 hours. After the reaction, the solvent was distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure.

(2) Under the protection of helium, 3g of silane coupling agent containing phosphaphenanthrene structure, 3g of 3-aminopropyltriethoxysilane, 0.1g of sodium hydroxide in methanol solution (0.1mg/mL), 2mL Deionized water and 20 mL of chloroform were added to the flask, and reacted at room temperature for 3 hours; then the temperature was raised to 80° C. for 4 hours. After the reaction, the product was slowly dropped into methanol at a volume ratio of 1:20 to precipitate a white powder, which was filtered, washed, and dried to obtain a trapezoidal polysiloxane with a molecular weight of 15648 and a phosphorus content of 8.1 wt%.

2. Preparation of trapezoidal polysiloxane modified bismaleimide/cyanate resin

Weigh 50g of N,N'-4,4'-diphenylmethane bismaleimide and 15g of bisphenol A cyanate into a beaker, stir mechanically at 135°C until the resin is completely dissolved to obtain a clear liquid; 9 g of the ladder polysiloxane prepared in this example was added to the liquid, and the prepolymer was mechanically stirred for 20 minutes to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuumize at 135°C for 1h, and then follow the processes of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 230°C/4h respectively After curing and post-treatment, a ladder-shaped polysiloxane modified bismaleimide/cyanate ester resin is obtained.

Example 8

1. Synthesis of trapezoidal polysiloxane

(1) Under nitrogen protection, 2.4g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1.9g vinyltriethoxysilane, 0.02g diphenyl peroxide Add formyl, 0.02 lauryl peroxide, 10 mL toluene, and 5 mL tetrahydrofuran into the flask, and react at 60°C for 8 hours. After the reaction, the solvent was distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure.

(2) Under nitrogen protection, mix 3g of phosphaphenanthrene structure-containing silane coupling agent, 5g of 3-aminopropyltriethoxysilane, 0.1g of sodium hydroxide in methanol (0.1mg/mL), 1mL Add deionized water, 10mL methanol and 10mL acetonitrile into the flask, and react at room temperature for 2 hours; then raise the temperature to 100°C for 0.5 hour. After the reaction, the product was slowly dropped into methanol at a volume ratio of 1:10 to precipitate a white powder, which was filtered, washed, and dried to obtain a trapezoidal polysiloxane with a molecular weight of 13436 and a phosphorus content of 7.6 wt%.

2. Preparation of trapezoidal polysiloxane/epoxy resin

Weigh 50g of bisphenol A epoxy resin (brand E-51) in a beaker, heat it to 70°C to become a low-viscosity liquid, add 25g of the trapezoidal polysiloxane prepared in this example, 2g of 2-ethyl-4- Methimidazole, mechanically stirred for 10 minutes to obtain a prepolymer. Pour the prepolymer into a preheated mold, vacuumize at 70°C for 20 minutes, and heat cure according to the processes of 80°C/2h+100°C/2h+120°C/2h and 140°C/4h to obtain a Ladder polysiloxane/epoxy.

Example 9

1. Synthesis of trapezoidal polysiloxane

(1) Under nitrogen protection, 1.9g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1.9g vinyltriethoxysilane, 0.04g azobicyclo Hexylcarbonitrile, 0.04g Add dimethyl azobisisobutyrate, 6 mL tetrahydrofuran, and 4 mL dimethylformamide into the flask, and react at 60°C for 6 hours. After the reaction, the solvent was distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure.

(2) Under the protection of nitrogen, 3g of silane coupling agent containing phosphaphenanthrene structure, 4g of 3-aminopropyltriethoxysilane, 0.1g of sodium hydroxide in methanol (0.1mg/mL), 1mL of Ionized water, 16 mL of acetone, and 4 mL of acetonitrile were added to the flask, and reacted at room temperature for 1 hour; then the temperature was raised to 80° C. for 2 hours. After the reaction, the product was slowly dropped into chloroform to precipitate a white powder according to a volume ratio of 1:10. After filtering, washing and drying, a trapezoidal polysiloxane was obtained with a molecular weight of 13144 and a phosphorus content of 8.2 wt%.

2. Preparation of trapezoidal polysiloxane modified bismaleimide resin

Weigh 45.7g N,N'-4,4'-diphenylmethane bismaleimide and 34.3g O,O'-diallyl bisphenol A in a beaker, mechanically stir at 135°C for prepolymerization After 15 minutes, a brownish-yellow transparent clear liquid was obtained. Add 5.3 g of the ladder polysiloxane prepared in this example into the liquid, and mechanically stir for 15 minutes to prepolymerize to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuumize at 135°C for 1h, and then follow the processes of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 230°C/4h respectively After curing and post-treatment, a ladder polysiloxane modified bismaleimide resin is obtained.

Example 10

1. Synthesis of trapezoidal polysiloxane

(1) Under nitrogen protection, 2.1g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1.9g vinyldimethoxysilane, 0.07g azobisiso Butyronitrile and 10 mL of toluene were added to the flask and reacted at 60°C for 6 hours. After the reaction, the solvent was distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure.

(2) Under the protection of nitrogen, 3g of phosphaphenanthrene structure-containing silane coupling agent, 6g of 3-aminopropyltrimethoxysilane, 0.1g of potassium hydroxide in methanol (0.1mg/mL), 1mL of deionized Add water and 25 mL of n-propanol to the flask, and react at room temperature for 2.5 hours; then raise the temperature to 65°C for 5 hours. After the reaction, the product was slowly dropped into ethanol at a volume ratio of 1:20 to precipitate a white powder, which was filtered, washed and dried to obtain a trapezoidal polysiloxane with a molecular weight of 132960 and a phosphorus content of 7.7 wt%.

2. Preparation of ladder polysiloxane/cyanate resin/bismaleimide resin

Weigh 40g of N,N'-4,4'-diphenylmethane bismaleimide and 40g of dicyclopentadiene cyanate in a beaker, and stir mechanically at 150°C; after the resin is completely dissolved, get The liquid was clarified; 18.03 g of the ladder polysiloxane prepared in this example was added to the liquid, and stirred mechanically for 30 minutes to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuumize at 150°C for 1h, and then follow the processes of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 240°C/4h respectively After curing and post-treatment, a ladder polysiloxane/cyanate resin/bismaleimide resin is obtained.

Example 11

1. Synthesis of trapezoidal polysiloxane

(1) Under nitrogen protection, 1.9g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1.9g vinyltriethoxysilane, 0.08g azobisiso Butyronitrile and 10 mL of n-propanol were added to the flask, and reacted at 100° C. for 10 hours. After the reaction, the solvent was distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure.

(2) Under the protection of nitrogen, 3g of phosphaphenanthrene structure-containing silane coupling agent, 3g of 3-aminopropyltrimethoxysilane, 0.1g of potassium hydroxide in methanol (0.1mg/mL), 1mL of deionized Add water and 10 mL of n-propanol to the flask, and react at room temperature for 1.5 hours; then raise the temperature to 75°C for 6 hours. After the reaction, the product was slowly dropped into ethanol at a volume ratio of 1:10 to precipitate a white powder, which was filtered, washed, and dried to obtain a trapezoidal polysiloxane with a molecular weight of 171,300 and a phosphorus content of 7.7 wt%.

2. Preparation of trapezoidal polysiloxane/cyanate resin

Weigh 30g of bisphenol A type cyanate in a beaker, stir mechanically at 150°C until the cyanate is completely dissolved to obtain a clear liquid; add 2.50g of the trapezoidal polysiloxane prepared in this example to the liquid, and mechanically The prepolymerization was stirred for 15 minutes to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuumize at 150°C for 1h, and then cure according to the process of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 240°C/4h And after treatment, a kind of ladder polysiloxane/cyanate resin is obtained.

Example 12

1. Synthesis of trapezoidal polysiloxane

(1) Under the protection of argon, 2.4g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1.9g γ-methacryloxypropyltrimethoxy Silane, 0.08g Add dibenzoyl peroxide and 15 mL of methanol into the flask, and react at 60°C for 8 hours. After the reaction, the solvent was distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure.

(2) Under the protection of argon, 3g of phosphaphenanthrene structure-containing silane coupling agent, 9g of 3-aminopropyltrimethoxysilane, 0.1g of potassium hydroxide in methanol (0.1mg/mL), 2mL of Ionized water and 30 mL of methanol were added to the flask, and reacted at room temperature for 0.5 hours; then the temperature was raised to 65°C for 8 hours. After the reaction, the product was slowly dropped into ethanol at a volume ratio of 1:5 to precipitate a white powder, which was filtered, washed, and dried to obtain a trapezoidal polysiloxane with a molecular weight of 249,180 and a phosphorus content of 8.1 wt%.

2. Preparation of trapezoidal polysiloxane/epoxy resin

Weigh 75g of bisphenol A epoxy resin (brand E-51) in a beaker, heat it to 70°C to make it a low-viscosity liquid, add 20g of the trapezoidal polysiloxane prepared in this example, 3g of 2-ethyl- 4-methylimidazole, mechanically stirred for 15 minutes to obtain a prepolymer. Pour the prepolymer into a preheated mold, vacuumize at 70°C for 20 minutes, and heat cure according to the processes of 80°C/2h+100°C/2h+120°C/2h and 140°C/4h to obtain a Ladder polysiloxane/epoxy.

Example 13

1. Synthesis of trapezoidal polysiloxane

(1) Under nitrogen protection, 2g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1.9g vinyltriethoxysilane, 0.08g azobisisobutyl Nitrile and 20 mL of dichloromethane were added to the flask and reacted at 60°C for 4 hours. After the reaction, the solvent was distilled off under reduced pressure to obtain a silane coupling agent containing a phosphaphenanthrene structure.

(2) Under the protection of nitrogen, 3g of silane coupling agent containing phosphaphenanthrene structure, 6g of 3-aminopropyltriethoxysilane, 0.1g of sodium hydroxide in methanol (0.1mg/mL), 1mL of Ionized water and 30mL of methanol were added to the flask and reacted at room temperature for 3 hours; then the temperature was raised to 60°C for 9 hours. After the reaction, the product was slowly dropped into methanol at a volume ratio of 1:10 to precipitate a white powder, which was filtered, washed, and dried to obtain a trapezoidal polysiloxane with a molecular weight of 251,740 and a phosphorus content of 7.9 wt%.

2. Preparation of trapezoidal polysiloxane modified bismaleimide/epoxy resin

Weigh 40g of bismaleimide resin and 7.5g of bisphenol A type epoxy resin in a beaker, mechanically stir at 135°C until the resin is completely dissolved to obtain a clear liquid; add 6.50g of this embodiment to the liquid The trapezoidal polysiloxane was prepolymerized with mechanical stirring for 15 minutes to obtain a prepolymer. Pour the prepolymer into the preheated mold, vacuum at 135°C for 30 minutes, and then cure according to the process of 150°C/2h+180°C/2h+200°C/2h+220°C/2h and 230°C/4h And after treatment, a kind of ladder polysiloxane modified bismaleimide/epoxy ester resin is obtained.

Claims (7)

1. a preparation method for ladder polysiloxane modified heat convertible resin, described ladder polysiloxane modified heat convertible resin by weight, comprises 100 parts of thermosetting resins and 1 ~ 50 part of ladder polysiloxane; Described ladder polysiloxane is simultaneously containing phospho hetero phenanthrene structure and amino group, and its structural formula is:

，

In formula, for elliptical segment;

R is R ₁or R ₂, wherein,

Simultaneously containing R1 and R2 in ladder polysiloxane molecular chain, and R1 is non-conterminous at ladder polysiloxane molecular chain homonymy; The molecular weight of described ladder polysiloxane is 900 ~ 3000000; It is characterized in that comprising the steps:

(1) under protection of inert gas, be that the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide of 0.9:1 ~ 1.1:1 mixes with the silane coupling agent containing vinyl by mol ratio, obtain mixture A;

(2) 1:50 ~ 1:100 in mass ratio, mixes initiator with mixture A, obtains mixture B;

(3) be dissolved in solvent S1 by mass concentration 0.2 ~ 0.5 g/mL by mixture B, under the condition of 30 ~ 120 DEG C, constant temperature stirs 2 ~ 20 hours, and after reaction terminates, solvent is removed in underpressure distillation, obtains the silane coupling agent containing phospho hetero phenanthrene structure;

(4) under protection of inert gas, the silane coupling agent containing phospho hetero phenanthrene structure step (3) prepared and the silane coupling agent containing amino in mass ratio 1:1 ~ 1:3 mix, and obtain mixture C; By catalyzer and mixture C in mass ratio 1:50 ~ 1:100 mix, obtain mixture D; Mixture D mixed with solvent S2 by mass concentration 0.2 ~ 0.5 g/mL, at room temperature stir 0.5 ~ 3 hour, be warming up to 40 ~ 100 DEG C, constant temperature stirs 0.5 ~ 10 hour; After reaction terminates, obtain mixture E;

(5) 1:5 ~ 1:20 by volume, slowly instills solvent S3 by mixture E, separates out white precipitate, filters, washing, dry, obtains ladder polysiloxane;

(6) the thermal curable resin of 100 parts of molten states and 1 ~ 50 part of ladder polysiloxane are mixed, through solidification, described can thermosetting resin be self heat-setting resin, or self can not the resin system that forms of the resin of thermofixation and solidifying agent, obtain a kind of ladder polysiloxane modified heat convertible resin;

Wherein, the described silane coupling agent containing vinyl is vinyltriethoxysilane or γ-methacryloxypropyl trimethoxy silane; Described is 3-aminopropyl trimethoxysilane or 3-aminopropyl triethoxysilane containing amino silane coupling agent.

2. the preparation method of a kind of ladder polysiloxane modified heat convertible resin according to claim 1, is characterized in that: described rare gas element is argon gas, nitrogen or helium.

3. the preparation method of a kind of ladder polysiloxane according to claim 1, is characterized in that: described initiator is one in Diisopropyl azodicarboxylate, 2,2'-Azobis(2,4-dimethylvaleronitrile), azo dicyclohexyl formonitrile HCN, azo-bis-iso-dimethyl or its combination.

4. the preparation method of a kind of ladder polysiloxane according to claim 1, is characterized in that: described initiator is one in dibenzoyl peroxide, dicumyl peroxide, dilauroyl peroxide, the special butyl ester of perbenzoic acid or its combination.

5. the preparation method of a kind of ladder polysiloxane according to claim 1, is characterized in that: described catalyzer is the methanol solution of potassium hydroxide or sodium hydroxide.

6. the preparation method of a kind of ladder polysiloxane according to claim 1, is characterized in that: described solvent S1 is C ₁~ C ₃alcohol, acetone, acetonitrile, methylene dichloride, trichloromethane, benzene, toluene, tetrahydrofuran (THF), dimethyl formamide or its combination.

7. the preparation method of a kind of ladder polysiloxane according to claim 1, is characterized in that: described solvent S2 or S3 is deionized water, C ₁~ C ₃alcohol, acetone, acetonitrile, trichloromethane or its combination.